Narrative:

Upon crossing fir, and reporting same to havana control, I recontacted kingston control (I had given them a gonis estimate approximately 10 mins prior), reported passing gonis at FL310, and requested descent for landing. As kingston control, acknowledged my report and cleared us to descend to 16000', my first officer said, 'hey, look at this!' and pointed above and to the right of us. It was an air carrier widebody transport quite close and apparently descending. We commenced our own descent immediately and heard air carrier widebody transport report to kingston control that he was out of FL320.2 for FL310. Kingston control was obviously confused and asked each of the aircraft to verify altitude and DME from montego bay VOR. Subsequently, altitude sep assignments were normal. It is obvious that the kingston controller lost track of who was where (and when), and assigned the air carrier widebody transport to descend on top of us to our altitude. Normally, we would have picked this up immediately by monitoring the radio. However, the altitude assignment apparently was made while one radio was being used to give the (gonis) fir position report to havana control, and the other radio was being used by the flight engineer to contact montego bay for the WX and gate assignment. Fortunately, visibility conditions were good and the first officer was alert. Although we were probably never closer than 1/4 mi latitude distance, the potential for collision was definitely there.

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Original NASA ASRS Text

Title: ACR WDB WAS DESCENDED TO AN ALT OCCUPIED BY ANOTHER ACFT IN A NON RADAR ENVIRONMENT.

Narrative: UPON XING FIR, AND RPTING SAME TO HAVANA CTL, I RECONTACTED KINGSTON CTL (I HAD GIVEN THEM A GONIS ESTIMATE APPROX 10 MINS PRIOR), RPTED PASSING GONIS AT FL310, AND REQUESTED DSCNT FOR LNDG. AS KINGSTON CTL, ACKNOWLEDGED MY RPT AND CLRED US TO DSND TO 16000', MY FO SAID, 'HEY, LOOK AT THIS!' AND POINTED ABOVE AND TO THE RIGHT OF US. IT WAS AN ACR WDB QUITE CLOSE AND APPARENTLY DSNDING. WE COMMENCED OUR OWN DSCNT IMMEDIATELY AND HEARD ACR WDB RPT TO KINGSTON CTL THAT HE WAS OUT OF FL320.2 FOR FL310. KINGSTON CTL WAS OBVIOUSLY CONFUSED AND ASKED EACH OF THE ACFT TO VERIFY ALT AND DME FROM MONTEGO BAY VOR. SUBSEQUENTLY, ALT SEP ASSIGNMENTS WERE NORMAL. IT IS OBVIOUS THAT THE KINGSTON CTLR LOST TRACK OF WHO WAS WHERE (AND WHEN), AND ASSIGNED THE ACR WDB TO DSND ON TOP OF US TO OUR ALT. NORMALLY, WE WOULD HAVE PICKED THIS UP IMMEDIATELY BY MONITORING THE RADIO. HOWEVER, THE ALT ASSIGNMENT APPARENTLY WAS MADE WHILE ONE RADIO WAS BEING USED TO GIVE THE (GONIS) FIR POS RPT TO HAVANA CTL, AND THE OTHER RADIO WAS BEING USED BY THE FE TO CONTACT MONTEGO BAY FOR THE WX AND GATE ASSIGNMENT. FORTUNATELY, VIS CONDITIONS WERE GOOD AND THE FO WAS ALERT. ALTHOUGH WE WERE PROBABLY NEVER CLOSER THAN 1/4 MI LAT DISTANCE, THE POTENTIAL FOR COLLISION WAS DEFINITELY THERE.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.